I've had trouble with the SW flicks on my Sony S470, just like the Alien set and Avatar CE. No in-playback issues as such, just a random failure to load the disc which needs the power plug pulled and the machine restarted.
Oh, when I play the UK discs in Region A mode I get the usual FBI warning and MPAA rating screens. It's a good bet that they're the exact same platters (only with better disc art) as the ones you guys will be getting this week. The UK packaging only lists the English language options, but there are actually several more audio languages and even more subtitles.